In order to perform such operations on bumper skins, use is already being made of machines of the type constituted by a bench carrying retractable structures, which in turn support punching and/or welding tools. Moving the retractable structures makes it possible to clear space above a location for receiving a bumper skin in order to make the skin easier to handle and to put into position. Once the skin is in place, the movable structures are returned to their operating position, thereby enabling the tools to operate. The operation of the tools may involve making use of actuators that move said tools in order to bring them into contact with the skin.
In addition to retractable structures, there are also provided removable and/or stationary protections (that may be intangible, e.g. being of the infrared curtain type) having a function of preventing any contact between a user and the tools while they are in movement, which tools are considered, as being dangerous because of their movements under drive from above-mentioned actuators. The protections are screens of large size that are interposed between the user and the skin, and they are optionally coupled to the retractable structures.
EP 1 798 019 discloses an example of such a screen, in the form of a safety light curtain and/or of a grid.